Atlantis Dispatch 007:
in which ATLANTIS contemplates acronyms, ASSEMBLY theory, and the summit of beauty and love…
Life-sized Venus De Milo recreated by Lego artist Nathan Sawaya. 2017
June 23, 2021
…begin transmission…
Not one, not two, but three missions to Venus! Between NASA and the European Space Agency, everyone seems to have gone wild for the planet that shines so brightly in the evening sky. Two NASA missions beat out two other Discovery Program proposals: one to explore Jupiter’s moon Io, and one to survey Saturn’s moon Triton, both with highly active landscapes. So, what was it? Why did the Venus missions win out? Did team Venus just have better names and acronyms? NASA certainly loves their acronyms. Reader, consider the nominees:
1. IVO: Io Volcano Observer (decent)
Mission: to check out all those volcanoes and learn how tidal forces shape planetary bodies.
2. Trident: (technically, not an acronym)
Mission: to explore Triton and understand pathways to habitable worlds at tremendous distances from the Sun.
3. DAVINCI+: Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging Plus (plus!—nice touch)
Mission: to measure the composition of Venus’s atmosphere, study how it formed and evolved, check out the tesserae, and figure out if it ever had an ocean.
4. VERITAS: Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy (notice the acronym *within* the acronym)
Mission: to map Venus’s surface, determine the planet’s geologic history, and understand why it developed so differently from Earth.
Now Atlantis will admit, between the Pixar-sounding “IVO” and the “Trident” evocations of sea gods and gum, we can see why DAVINCI+ and VERITAS won the prize, and yet we still find ourselves puzzled. After all, old Atlantis is a simple ship with a simple name, and we do not always understand these glinting fancy things.
In our bemusement, the crew sailed back into the annals of our own archive, and recalled that strange week back in the autumn of 2020, when a compound in the Venusian atmosphere revealed itself and grabbed our attention by the bowsprit. You know, the week we lovingly refer to as the “Great Phosphine Freakout.” As you may recall from our first dispatch, Atlantis reflected on the dispute that broke out between the scientists who said that their phosphine measurements indicated that there is life in Venus’s atmosphere, and the scientists who argued that the data might be bad, or that the findings could have been caused by geochemical phenomena like Venus’s many, evidently active, volcanoes.
So, when these two missions won the proposal party, Atlantis, was like, well, wait, what? Why go only there? What about all of the other potential planets and exoplanets to explore? Didn’t Venus, like, kind of cry wolf on life already? Now we know, we know, it’s not the planet’s fault that it has this saucy reputation, but still. We wondered, and then we wandered into an investigation on the matter. What we found, in this great Venusian mystery, follows:
Basically, it seems that NASA has chosen its two Venus missions to discover how Venus became such a fiery world when it seems that once, so very long ago, it was a habitable planet, just like Earth. The program won’t investigate whether past Venusian life turned its own planet into a dumpster fire of climate altering junk before it lost its habitable atmosphere, but both missions will use new instruments to get to know the details of Venusian geography and atmospheric chemistry. Basically, Venus is the closest experimental proxy to Earth for understanding why we have an atmosphere rather than fiery toxic gasses. In short, it looks like the new Venusian missions are steering clear, at least for now, from any direct hunt for life, but they might be able to tell us something about how and why life disappears.
As you may have guessed, life has a special place in the hull of old Atlantis, and though Venus’s gurgling and spewing atmosphere seems to have something oracular about it, we found ourselves tempted to sail elsewhere for the day, to see what other islands of possibility might be out there in the great sea of science.
And BAM! It turns out that on a grand island, not so far from the Outer Hebrides, we landed on an amazing piece of work, one that took us right into the molecular crux of living things. Reader, we learned about ASSEMBLY (Alien Search Simplified. Enumerate Molecular Build. Life? Yay!) Whoa!
And WOE (What On Earth), you ask? Well, let’s just say that ASSEMBLY theory is the beginning of a great adventure that will take us far beyond Earth, with a very exciting technique dedicated to the hunt for living systems.
This month, a group of scientists, including Cole Mathis and frequent Atlantis muse, Sara Walker, released a paper that offers both a theory and the technological specifications for a new life-detection technique. The work, led by Lee Cronin, Regius Professor of Chemistry at the University of Glasgow, is a major advance for the hunt for life using technology that we currently possess.
The team noticed that the structures of living systems, and the structures of objects that are the consequences of living systems – like Iphones, astrolabes and Lego playsets – are far more complex than simple non-living stuff. So, they devised a way for us to quantify an object’s level of complexity based on how difficult it is to assemble, or how many steps it takes to piece together.
To put it plainly, the higher the MA (Molecular Assembly) number, the more complex the object. It’s sort of the same reasoning Lego employs when they put age numbers on their sets. This 15-piece animal train has an LA (Lego Age) of 1.5, while this 7,500+ piece Millennium Falcon has an LA of 16. Why? Because it’s a heck of a lot more complicated to assemble. Count your lucky stars that Lego includes detailed instructions!
To elaborate just a bit more, not only are complex objects not likely to be randomly produced, but complex objects that appear in any kind of abundance are even less likely to arise spontaneously. Abundance, you say? Yes, indeed! In a recent interview, Cole Mathis explained that “living systems tend to create complex molecules in detectable abundance.” So, you might just get an animal train by banging those big baby-bricks together at random. Sure. But the odds of getting a Millennium Falcon? Extremely Low. Five hundred Millennium Falcons? Please!
The very same can be said for life.
The researchers argue, therefore, that complex molecules found in high abundance can serve as biosignatures. Perhaps the coolest thing about their work is that they not only produce the super rad Molecular Assembly Index (which is a combined measure of assembly steps and abundance), but they also deliver a way to do the measuring.
How, you ask? By making use of a tandem mass spectrometer (think big bad laser) to scan curious objects and assess their complexity. The researchers pointed their lasers at a variety of samples ranging from dead to alive, abiotic to biotic, even weirdo blinded samples direct from NASA, to test their index out, and lo, a magical threshold emerged. It seems that anything beyond fifteen assembly steps is unequivocally a living system, or the consequence of a living system. As Cronin explained in a meeting at the Santa Fe Institute this past spring, “when you get to an assembly number that is fifteen or higher, the chances that the object was produced by a random event goes to one in a mol [6.22*1023].” **
Now, this does not mean that all products of life are 15+ steps complex. After all, it seems we might pass over decayed space yeast. But fear not, we will find the beer. We will not miss the whiskey!
As it turns out, NASA is as excited about this project as it is about Venus, which is to say a whole lot, and when we send our next missions into space — say to Europa, Io, Triton, or Titan – the spectrometers will be ready to scan the solar system for sure-fire signs of life. It turns out that the mass specs on the Mars Rovers are fairly sophisticated, so we’re poised to pew pew anything interesting, break it up into its molecular bricks and, ABRACADABRA, just like that, compute the complexity!
Atlantis hopes that both the DAVINCI+ and VERITAS missions will be likewise equipped. Venus is hot! She’s mean. Acid rain, but no water? There is most certainly a lot of interesting chemistry to observe. And by “interesting chemistry” we do not mean phosphine. Neither does Cole. After all, as he reminded us, its MA is only 1. 1? How Boring! Even Assemb-Lee Cronin agrees.
Yours in exploration,
ATLANTIS (Always Thinking of Life And Navigating The InterPlanetary Seas)
** The next time someone tells you you’re one in a million, Atlantis thinks you should turn tail and walk away. Reader, you’re truly special. You’re one in a mol!
Tune in next time, when Atlantis contemplates whether or not life in the universe is looking for us...